Battery terminal connector



Nov. 29,1960 E. LA RUE JOHNSON ETAL 2,

' BATTERY IERMiNAL CONNECTOR filed June 9, 1958 2 Sheets-Sheet 1 INVENTOR. E lber/ L. Johnson BY Will/27m K. Jensen 7' heir Af/or/gey Nov. 29, 1960 E. LA RUE JOHNSON ET AL 6 ,689

BATTERY TERMINAL CONNECTOR Filed June 9, 1958 2 Sheets-Sheet 2 7 2:; x I "8' Fig 5c INVENTOR. E/ br/ 1.. Johnson l I WII/10m K. Jensen f l4 g. 6 W,

The/r Attorney BATTERY TERMINAL CONNECTOR Elbert La Rue Johnson Warren, Ohio, and William Kenneth Jensen, Royal Oak, Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed June 9, 1958, Ser. No. 740,891

'3 Claims. (Cl. 339-95) This invention relates to an electrical connection and particularly to a battery terminal connector having an improved battery-post engaging portion.

An object of this invention is to provide a new and improved battery terminal connector adapted to provide high pressure contact with increased holding force relative to a predetermined area of the battery terminal connector engageable against a battery post.

Another object of this invention is to provide a battery terminal connector having a post engaging portion provided with a generally truncated inner peripheral surface interrupted by a substantially cylindrical auxiliary section added purposely for effecting a high pressure contact over a reduced area providing improved electrical conductivity, increased holding force against vibration, and

improved sealing against lead corrosion that would result in poor or broken electrical contact.

Another object of this invention is to provide a battery terminal connector having a battery-post engaging portion provided with a generally truncated inner peripheral surface interrupted by a substantially cylindrical portion terminating at one end in a ridge located radially inwardly from the truncated surface for biting into a coating which is forced aside both relative to the connector cylindrical portion and a battery post whereby bare metal for better contact is exposed for improved electrical conductivity through the surface area of the substantially cylindrical portion.

Another object of this invention is to provide an improved battery terminal connector on which loose parts such as a battery bolt, nut and bushing are eliminated together with a reduction in an amount of cast metal in which there is embedded a spring insert located concentrically relative to a substantially cylindrical auxiliary section projecting inwardly from a tapered inner annular terminal connector surface.

. A further object of this invention is to provide a battery terminal connector having in combination the following parts including a cast-metal substantially cornplementary battery-post-engaging portion having ends terminating adjacent to a lateral opening at one side, including a spring metal insert embedded in the batterypost-engaging portion and provided with interleaving extensions protruding in opposite directions from the ends adjacent to the lateral opening and terminating with resilient free ends at least three in number to define a plane relative to which a force must be applied to spread the spring insert for disengagement of the connector, and including both an inner tapered surface of the cast metal portion provided extending at an angle relative to the .spring insert and an inwardly-extending auxiliary cast metal cylindrical portion substantially in parallel and concentric relation to the spring insert that normally exerts a force radially inwardly relative to an inner annular suface area of the auxiliary cylindrical portion used for scraping clean a surface on a tapered battery post through which current can flow relative to the tates Patent inner annular surface area of the auxiliary cylindrical portion with improved electrical conductivity maintained due to improved sealing of the connector relative to the battery post and the auxiliary cylindrical portion.

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a perspective view of a portion of a battery with a post and a battery-post engaging terminal connector for contact therewith in accordance with the present invention.

Fig. 2 is a plan view of the connector in Fig. 1.

Fig. 2a is a cross sectional view taken along line 2a2a of Fig. 2.

Fig. 3 is an end view of the connector shown in Fig. 2. Fig. 4 is a side view of the connector in Fig. 2. Fig. 5 is a plan view of another embodiment of a battery terminal connector in accordance with the present invention.

Fig. 5a is a side view of the connector in Fig. 5. Fig. 5b is an end view of the connector in Fig. 5.

Fig. 5c is a side view of a spring insert used in the connector of Fig. 5.

Fig. 6 is a fragmentary enlarged cross sectional view of an electrical connection between a tapered battery face 12s relative to which a battery terminal connector generally indicated by numeral 14 is engageable. The

battery post 12 is made of a metal alloy including an timony and tin in predetermined ranges added to lead for hardening purposes. A battery terminal connector 14 is suitably attached to a cable or wire: 15 which is joined to the battery terminal connector at one side orend thereof by means of a cable connecting portion 146. The specific way of connecting the cable 15 with the cable connecting portion is not part of this invention. Suffice it to say that the battery terminal connector 14 is provided with a body portion 14b which is prefer-j ably formed of a cast metal alloy including at least 33 /2% antimony, /21% tin and a remainder of lead except for maximum impurities. alloy ranges are provided in the metal of the battery terminal post 12. However, it is possible for the alloy to include tin in ranges up to 2 and 3% and antimony in"- ranges up to 712% with a remainder of lead except tor maximum impurities.

' The body portion 14b of the battery terminal con nector 14 includes a pair of substantially complemen tary legs or arms 14a and 14A each having a semi-annular shape with one end of each of the arms integral with the body portion 14b adjacent to the cable connecting end 14c and each having an opposite free end 14c and 14B respectively. The ends 142 and 14E are located opposite each other and are separated by a gap 14g which is adjacent to a central opening or battery post aperture 14G. The aperture 14G extends through the battery-- terminal connector 14 and the cast metal of lead alloy is formed'to provide a'tapered inner" peripheral surface defining lateral extremities of the central aperture 14G as is more clearly visible in the views of Fig. 2a and Fig. 4.

As shown particularly in Fig. 2a, there is a'n'upper tapered surface MT and a lower tapered surface 14: providing a truncated inner peripheral wall which would: be continuously angularly disposed relative to a substan-j Preferably the same tially cylindrical spring metal insert or spring steel band generally indicated by numeral 16 except for a substantially cylindrical auxiliary section or interrupted portion generally indicated by numberal 18. This substantially cylindrical auxiliary portion of the body portion of the cast metal connector body provides a predetermined surface area which is substantially parallel and concentric relative to the spring metal insert 16. As seen best in Fig. 2a, the tapered surface along the inner periphery of the battery terminal connector is progressively greater in a radial dimension as the surface progresses toward the bottom of the battery terminal connector. Preferably the auxiliary cylindrical portion 18 is provided in a slightly off-center position between the top and bottom of the terminal connector aperture and as seen in Fig. 2a as well as in the outline of the aperture and auxiliary cylindrical portion in Fig. 4, the auxiliary cylindrical portion is located so as to provide a greater part of the substantially cylindrical surface above a median height between the top and bottom of the battery terminal connector. However, it is to be noted that a lower edge 18E of the inner surface of the auxiliary cylindrical portion 18 is provided slightly below the halfway mark between the upper and lower ends of the aperture through the battery terminal connector. The edge 18E results from the difference in radial dimension between the cylindrical portion relative to the tapered surface surrounding the aperture 146 and the edge 18B is located at one end of a radially or substantially laterally extending ridge 18R which extends below the substantially cylindrical portion and provides a connection between the cylindrical portion and the lower tapered surface 14!. The purpose of the ridge 18R and edge 18Ewill be more fully described below.

The battery terminal connector in accordance with the present invention requires a reduced number of parts and a reduced amount of lead or alloy for the body portionbecause the spring metal insert 16 is adapted to permit establishment of a resilient connection relative to a battery terminal post in conjunction with the substantially cylindrical auxiliary portion 18 mentioned above. Further details of the spring insert for the battery terminal connector are visible in Figures 1, 2, 3, and 4. The spring insert is a substantially U-shaped member as indicated by a dotted line outlining the insert as it extends through the opposite arms 14a and 14A of the body portion of the battery terminal connector. The spring insert, however, has opposite ends which protrude to form an interleaving structure including at least three extensions or projections. For forming these extensions the spring insert is preformed or bent to have corners 16c and 16C formed substantially adjacent to the gap 14g and connected with radially outwardly extending segments 16s and 16S terminating in end projecting portions 16E and Me. The ends 16e and 16E are bent to be substantially transverse to the segments 16.; and 168 which serve to space projecting ends Me and 16B a predetermined distance away from the cast metal ends 14E and Me of the body portion of the battery terminal connector.

As shown in Fig. 3, there are preferably two ends 16E projecting from one of the ends of the cast metal body and these two are bent to extend in a plane coincident with an intermediate projecting end 16e of the spring insert which extends in an interleaved type of structure visible also in Fig. 1. Since the end projections 16B are provided on opposite sides of the intermediate projection 16a there are at least three free ends of the spring insert which are engageable by a tool such as a pair of pliers 16P illustrated partially in Fig. 1. A space or gap 166 between the end projections 16E has sufficient height to permit the intermediate end projections 16a to extend between outer projections 16E. However, the height of the gap 16G is only slightly greater in width than the height dimension of the intermediate end projection 162 r thereby permitting a tool such as the pliers MP to engage the intermediate end projection 16a with one jaw 16 and an opposite jaw 16] engages inner corners 16x of the projecting ends 16E. Thus a positive grip in a single plane defined by the corners 16x and a free end of the end projection 16:: can be obtained by using the pliers 16F to urge the corners 16x and end projection 16e closer toward each other. As the tool or pliers is used to squeeze the ends toward each other, the gap 14g between ends of the arms of the battery terminal connector is increased in size and simultaneously the aperture 14G is also increased in size so as to be larger than the external annular surface 12s of the battery terminal post 12.

As further outlined in Fig. 2, the spring insert can be provided with a pair of diametrically oppositely located radially outwardly extending indentations or embossed portions 161 and 16 adapted to provide increased resilience relative to the flexing of opposite free ends 16a and 16E of the spring insert 16. Preferably the insert is made of a flat strip of spring steel approximately 0.060 to 0.100 inch thick. The insert is heat treated and electroplated to be resistant to corrosion and the insert is cast into the terminal and is completely enclosed except for the end projections or tab portions 16c and 165. These end projections or tab portions provide a hard surface permitting a pair of pliers to be used to spread the terminal to facilitate its assembly or its disassembly rela tive to the terminal post of a battery.

A modification of the terminal in accordance with the present invention is shown in Fig. 5 wherein spring insert identified generally by numeral 26 is provided for the battery terminal connector and terminates adjacent to the cast ends 14B and 14a of the connector body adjacent to east end auxiliary portions 24E and 24e formed integrally with ends 14E and 14e respectively. The spring insert 26 is provided with opposite ends 2613 and 262 having apertures 26A and 26a extending through the ends so as to permit lead alloy to be cast through the apertures for anchoring the spring insert ends relative to the cast metal body of the battery terminal connector. The ends 26E and 26e are substantially parallel to each other and extend radially outwardly away from an inner aperture 146 of the battery terminal connector. A space 26;; is provided between the parallel ends of the insert 26 and the spring insert ends 26E and 26e are adapted to provide hard surfaces opposite each other and adapted to be engaged by a tool such as a screwdriver which may be inserted between the ends of the spring insert for urging opposite arms 14A and 14a of the battery terminal connector away from each other to increase the size of the aperture 146 relative to the battery terminal post 12. Insert 26 is provided with embossed radially outwardly projecting portions 26U and 26a for the purpose of increasing resilience relative to the opposite free ends of the insert. It is to be noted that the embossed portions of the insert in both embodiments of the battery terminal connector of the present invention serve also to improve anchoring of the spring insert relative to the cast metal body portion of the battery terminal connector. Side and end views of the battery terminal connector of Fig. 5 are provided in Figures 5a and 51; respectively. As indicated by the dotted lines in Figures 5a and 5b the battery terminal connector having the modified spring insert 26 is also provided with the auxiliary cylindrical portion 18 described with Figures 2a and 4. Identical reference numerals are used in the drawings of Figures 5, 5a, and 5b to illustrate parts and portions thereof comparable to those described with the battery terminal connector shown in Figs. 14.

Fig. 5c illustrates a side view of the spring insert 26 and multiple apertures are illustrated similar to the apertures 26a and 26A extending through the spring insert 26 as mentioned earlier. Any number of these apertures through the spring insert can be provided to improve the integral casting of a body portion around the insert.

Fig. 6 is an enlarged fragmentary cross sectional view showing abattery terminal connector in accordance with the present invention and a battery terminal post relative to which the connector has been assembled. As mentioned earlier the battery terminal post has a tapered outer peripheral surface and the battery terminal connector is provided with both an upper tapered surface 14T and a lower tapered surface 14!, each having the same general truncated shape as the tapered outer surface 12s of the battery terminal post 12. A spring insert 16 is shown in the cross sectional view of Fig. 6 and as noted earlier this spring insert is substantially parallel and concentric relative to the auxiliary cylindrical portion 18 cast integrally with the body portion of the battery terminal connector. The ridge 18R and edge 18E of the battery terminal connector auxiliary portion 18 is shown in the cross sectional view to illustrate clearly how the ridge and edge efiectively bite into or scrape away a crust or coating of oxide and lead sulphide material which forms on the inner surface of the battery terminal connector and outer surface of the battery terminal post.

In previous connections it has been found that the tapered inner surface and tapered outer surface of the battery connector and most respectively are complementary to each other. Electrical conductivity obtained by such engagement of such complementary tapered surface is decreased due to presence of the oxides or crust which may even include dirt and other foreign material. Since relatively large currents must be carried by the connection between the battery post and terminal connector, it has been found that particularly good electrical conductivity is required when loose parts such as battery bolts and nuts and bushings are eliminated and replaced by use of a spring insert such as shown in the drawings. Furthermore, a substantially good electrical contact is often difiicult to obtain when using a spring insert because a positive strengthening of the clamping action of the terminal connector relative to the post cannot be provided by tightening a nut onto a bolt which is completely eliminated. Preferably the aperture 146 extending through the battery terminal connector is cast undersize so that the battery terminal connector can be sprung onto the post and is held resiliently in position by the spring insert 16 or 26. Usually battery terminal connections have been made by using a large surface combined with low pressure to obtain sufficient contact for suitable electrical conductivity between a battery post and terminal. However, since batteries are often mounted in locations on motor vehicles wherein vibration becomes excessive, a low pressure connection such as has been used previously results in a loosening of the connection with resulting decrease in electrical conductivity and increase in electrical resistance. Loosening of the engagement of adjacent complementary surfaces results in greater separations of the electrical contact due to increased susceptibility to corrosion which may cause deterioration of adjacent surfaces to the extent that there is even more decrease in electrical conductivity and increase of electrical resistance. In using a battery terminal connector having a nut and bolt for tightening opposite ends of the connector into a more tightly engaged position, it is possible to obtain an electrical connection in which less adjacent surface area is required in conjunction with greater or larger pressure exerted by the terminal connector relative to the battery terminal connection. When only a small surface approaching annular line contact of the battery terminal connector relative to the battery terminal connector post is used, there is generally insufficient surface area for providing an optimum electrical conductivity. Furthermore, as a spring insert is used having a generally circular configuration, there is in effect only an annular or planar pressure exerted between a very narrow radially inwardly extending ridge through which force would be exerted relative to a battery terminal post.

7 One of the advantages of the structure of thebattery terminal connector in accordance withthe present invention lies in the provision of a substantially cylindrical auxiliary portion provided with the cast metal body along the inner periphery of the battery terminal connector and the ridge 18R and edge 18e serving to bite or scrape away a crust of impurities such as lead sulphide or oxide or dirt as generally indicated by numeral 28 in Fig. 6. Similar foreign material 28p is located on an inner peripheral surface of the battery connector. The ridge and edge clear away this foreign material from a surface 128 of the battery terminal post which is distinct from the tapered surface 12s over which the crust is located. The ridge 18R pushes aside the foreign material and dislocates this material into a pocket 28P in which the foreign material 28 and 28p can be compressed. Sliding frictional engagement of the radially inner cylindrical surface of the auxiliary portion 18 would also result in a scraping or cleaning of this auxiliary surface such that some foreign material would be displaced to a pocket or recess 28R containing foreign material 28r adjacent to an annular edge 18r formed by a junction between an upper annular end of the auxiliary portion 18 and a lower annular end of upper tapered surface 14T. Since the spring insert 16 or 26 provided with the battery terminal connectors in accordance with the present invention is substantially parallel to and concentric relative to the surface of the auxiliary portion 18 and the scraped clean surface 128 of the battery po'st,a good electrical connection with optimum electrical conductivity is obtained between adjacent surfaces having a predetermined cylindrical area relative to each other. A locking of the electrical connector relative to the battery terminal post occurs between the auxiliary cylindrical portion 18 and the battery post such that radially inwardly exerted force from the spring insert is distributed evenly relative to these adjacent surfaces due to the parallel and concentric relationship of the spring insert and auxiliary cylindrical portion 18. The concentricity assures elimination of transverse components of force which would cause poor connection and loosening under vibration. A good clean surface is provided between the adjacent connector and battery post surface areas and in effect there is a seal along the top and bottom edges of the surfaces provided by the compressed foreign material 28;) and 28r located in pocket 28F and recess 28R. In addition to the sealing function served by the foreign material in these pockets or recesses, the foreign material is compressed in this space and enhances the locking action of the terminal connector relative to the battery terminal post because packing of the foreign material appreciably above and only slightly below the median height of the post causes increased filling adjacent to where compressive engagement by the connector occurs relative to the post. Thus the sealing effect results in resistance to corrosion along the adjacent clean surfaces between the battery terminal post and the auxiliary cylindrical portion 18. As illustrated in Fig. 6 a tight connection between the battery terminal connector and battery post is obtained such that the tapered surfaces of the connector and post are complementary to each other except for the auxiliary cylindrical portion 118 that extends radially inwardly.

It is well known that corrosion is one of the greatest problems involved in making an electrical connection between a battery post and terminal connector. This corrosion can result in poor electrical conductivity but such corrosion is kept away from the actual clean surfaces through which the electric current must flow intermediate sealing pockets or recesses for foreign material as provided with the auxiliary cylindrical portion 18 engageable relative to the battery terminal post as illustrated in the enlarged view of Fig. 6. With the connector of the present invention, vibration and loose connection can be avoided, and also there is better electrical conductivity with higher contact pressure over a small cylindrical surface area relative to which the spring insert is located in parallel and concentric relationship. Loose parts are eliminated and time for assembling or disassembling a connector with a battery post is reduced.

While the embodiments of the present invention as herein disclosed constitute a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A battery terminal connector, comprising a C- shaped body having a tapered opening adapted to engage a tapered battery terminal post, said body having axially spaced end portions forming a discontinued inner tapered surface, said body further having a central portion intermediate and axially adjacent said end portions and having a cylindrical inner surface, the cylindrical surface being of the same diameter as the adjacent edge of one of said tapered surfaces and forming a radial shoulder with the other of said tapered surfaces, said shoulder extending radially inwardly past the discontinued tapered surface whereby a cutting edge that embeds within the tapered battery terminal post is formed, a metallic spring member having a C-shaped cylindrical part positioned radially outward from said central portion and embedded in said body and second parts extending substantially radially outwardly adjacent the circumferential opening of said shaped body, said second parts terminating with means adapted to be engaged for biasing the second parts apart. 2. The battery terminal connector of claim 1 wherein the body portion is relatively more soft and less resilient than the spring member.

3. A battery terminal connector comprising, a C-shaped body having a tapered opening adapted to engage a tapered battery terminal post, said body having axially spaced end portions having inner surfaces forming parts of a conical surface, said body further having a central portion having a cylindrical surface intermediate and,

axially adjacent said end portions, said cylindrical surface being of the same diameter as the adjacent end of one of the end portions and forming a radial shoulder with the other end portion, said shoulder extending radially inwardly past the conical surface whereby a cutting edge that embeds within the tapered battery terminal is formed,

and a cylindrical circumferentially open reinforcing spring member positioned radially outward of said central portion and fixed to said body.

References Cited in the file of this patent UNITED STATES PATENTS 

